Merging Photoinduced Electron Transfer with Hydrogen Atom Transfer: Formal β-C(sp³)-H Pyridination of Carbonyls

In this study, a novel approach that combines photoinduced electron transfer (ET) with hydrogen atom transfer (HAT) has been introduced for the selective β-C(sp³)-H pyridination of carbonyl compounds. This method is notable for its absence of transition metals and its ability to function under benign reaction conditions, resulting in a range of pyridinated carbonyl derivatives with consistently moderate to good yields. The significance of this technique is further underscored by its potential for the late-stage functionalization of pharmaceutically significant molecules. Mechanistic investigations confirmed that the reaction proceeds via a radical-mediated pathway.